Mitochondrial DNA (mtDNA) mutations are the major cause of mitochondrial diseases. Cells harboring disease-related mtDNA mutations exhibit various phenotypic abnormalities, such as reduced respiration and elevated lactic acid production. Induced pluripotent stem cell (iPSC) lines derived from patients with mitochondrial disease, with high proportions of mutated mtDNA, exhibit defects in maturation into neurons or cardiomyocytes. In this study, we have discovered a small-molecule compound, which we name tryptolinamide (TLAM), that activates mitochondrial respiration in cybrids generated from patient-derived mitochondria and fibroblasts from patient-derived iPSCs. We found that TLAM inhibits phosphofructokinase-1 (PFK1), which in turn activates AMPK-mediated fatty-acid oxidation to promote oxidative phosphorylation, and redirects carbon flow from glycolysis toward the pentose phosphate pathway to reinforce anti-oxidative potential. Finally, we found that TLAM rescued the defect in neuronal differentiation of iPSCs carrying a high ratio of mutant mtDNA, suggesting that PFK1 represents a potential therapeutic target for mitochondrial diseases.

线粒体 DNA (mtDNA) 突变是线粒体疾病的主要原因。携带疾病相关 mtDNA 突变的细胞表现出各种表型异常，例如呼吸减少和乳酸产生升高。源自线粒体疾病患者的诱导多能干细胞 (iPSC) 系具有高比例的突变 mtDNA，在成熟为神经元或心肌细胞方面表现出缺陷。在这项研究中，我们发现了一种小分子化合物，我们将其命名为色氨酸酰胺 (TLAM)，它可以激活由患者来源的线粒体和来自患者来源的 iPSC 的成纤维细胞产生的胞杂的线粒体呼吸。我们发现 TLAM 抑制磷酸果糖激酶 1 (PFK1)，进而激活 AMPK 介导的脂肪酸氧化以促进氧化磷酸化，并将糖酵解中的碳流重新导向戊糖磷酸途径，以增强抗氧化潜力。最后，我们发现 TLAM 挽救了携带高比例突变 mtDNA 的 iPSC 的神经元分化缺陷，这表明 PFK1 代表了线粒体疾病的潜在治疗靶点。